Please use this identifier to cite or link to this item: http://hdl.handle.net/2440/98712
Type: Theses
Title: Sarcopenia in older people
Author: Yu, Solomon Ching Yeh
Issue Date: 2014
School/Discipline: School of Medicine
Abstract: Under-nutrition and weight loss in older people remain poorly recognized and so are undermanaged. Those at nutritional risk, and especially those losing weight, experience a loss of muscle mass referred to as sarcopenia, which is related to many different adverse health outcomes, including falls and increased risk of fracture. Although research into the condition has gained momentum over the last two decades, especially for those aged eighty years and older, research has predominately been conducted overseas. In Australia, very few studies have investigated the prevalence of sarcopenia in our older population. Local evidence is required in order to inform Australian policy makers and the health and aged care sector. Furthermore, in spite of the increasing call for appreciation, screening and early diagnosis of the condition, there is no consensus as to a preferred screening method. Without acceptable clinical screening tools, identification of sarcopenia continues to be problematic. It is therefore important to develop a simple clinical test to facilitate early detection in primary or aged care settings as part of continuing and increasing Australian research into sarcopenia. Additionally, whilst appetite loss is known to be a contributing factor, the relationship between inflammation and appetite loss in healthy individuals with no recent history of weight loss is unclear. The aims of this thesis were therefore: (1) to identify the prevalence of sarcopenia in primary care; (2) to develop and validate simple anthropometric prediction equations (PE) for lean body mass (LBM) and appendicular skeletal muscle mass (ASM); (3) to determine the performance of the ASM PE compared to dual absorptiometry x-ray assessment (DXA) of ASM in combination with grip strength; and (4) to explore the association between cytokines and appetite in a healthy population. Research from this doctoral thesis has confirmed that sarcopenia is common in community dwelling older Australians and increases with age. Anthropometric prediction equations for LBM and ASM were developed and validated: LBM= 22.932326 + 0.684668 (weight) - 1.137156 (BMI) -0.009213 (age) + 9.940015 (if male) and ASM= 10.047427 + 0.353307 (weight) - 0.621112 (BMI) - 0.022741 (age) + 5.096201 (if male). Cut-offs for low muscle mass for use in Australia was also developed. The use of ASM PE for the identification of low muscle mass, in combination with a measure of low muscle function, such as grip strength, performs well as a ‘rule out’ screening test for sarcopenia when compared to the diagnostic test of ASM assessed using DXA in combination with low grip strength. At the same time, appetite was found to be negatively associated with serum levels of pro-inflammatory IL-1ß and positively associated with serum levels of anti-inflammatory cytokine IL-10 in apparently healthy people with no recent weight loss. Research from this doctoral thesis has contributed to increased awareness that sarcopenia is common and this will aid early intervention. At the same time, a clinical screening tool to support the early diagnosis of sarcopenia was developed.
Advisor: Adams, Robert John
Visvanathan, Renuka
Wilson, David Hugh Dunlop
Dissertation Note: Thesis (Ph.D.) (Research by Publication) -- University of Adelaide, School of Medicine, 2014.
Keywords: Sarcopenia
muscle mass
appendicular skeletal muscle mass
grips strength
lean body mass
weight
prediction equations
prevalence
appetite
cytokine
inflammation
Provenance: This electronic version is made publicly available by the University of Adelaide in accordance with its open access policy for student theses. Copyright in this thesis remains with the author. This thesis may incorporate third party material which has been used by the author pursuant to Fair Dealing exceptions. If you are the owner of any included third party copyright material you wish to be removed from this electronic version, please complete the take down form located at: http://www.adelaide.edu.au/legals
Copyright material removed from digital thesis. See print copy in University of Adelaide Library for full text.
Appears in Collections:Research Theses

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